means that the dynamic linker gets mapped in at the top of available
user virtual memory (typically just below the stack), shared libraries
get mapped downwards from that point, and calls to mmap() that don't
specify a preferred address will get mapped in below those.
This means that the heap and the mmap()ed allocations will grow
towards each other, allowing one or the other to grow larger than
before. Previously, the heap was limited to MAXDSIZ by the placement
of the dynamic linker (and the process's rlimits) and the space
available to mmap was hobbled by this reservation.
This is currently only enabled via an *option* for the i386 platform
(though other platforms are expected to follow). Add "options
USE_TOPDOWN_VM" to your kernel config file, rerun config, and rebuild
your kernel to take advantage of this.
Note that the pmap_prefer() interface has not yet been modified to
play nicely with this, so those platforms require a bit more work
(most notably the sparc) before they can use this new memory
arrangement.
This change also introduces a VM_DEFAULT_ADDRESS() macro that picks
the appropriate default address based on the size of the allocation or
the size of the process's text segment accordingly. Several drivers
and the SYSV SHM address assignment were changed to use this instead
of each one picking their own "default".
sa_switch() invocations while exiting. Test P_SA instead of L_SA, out
of paranoia. Avoids a possible remrunqueue panic reported by Havard
Eidnes.
Release the kernel lock before calling the userret function to exit in
sigexit(). Problem noted by Paul Kranenburg.
timeout
the semantics of 'timeout' parameter differ to POSIX for the syscall
(not const, may be modified by kernel if interrupted from the wait) -
libc will provide appropriate wrapper
since sigwaitinfo(2) will be implemented as wrapper around sigtimedwait()
too, remove it's reserved slot and move sigqueue slot 'up', freeing
slot #246
(XXX sa_yieldcall() and sa_switchcall() should be combined and take
arg as the function to call, but I'm somewhat nervous about void *
vs. void (*)()).
conditions at points where it's necessary to access both the up-stream
and down-stream parts of the bi-directional pipe data structure. These
are marked `XXXSMP' in the code.
Also, since the changes are pretty invasive, there little point in keeping
all the "#ifdef FreeBSD" code around; so all of that has been stripped out.
kernel config option) that controls whether the kernel dumps to the
dump device on panic. Dumps can still be forced via the ``sync''
command from ddb. Defaults to ``on''.
* Change the semantics of proc_unstop() slightly, so that it is
responsible for making all stopped LWPs runnable, instead of
all-but-one. Return value is a LWP that can be interrupted if doing
so is necessary to take a signal. Adjust callers of proc_stop() to
the new, simpler semantics.
* When a non-continue signal is delivered to a stopped process and
there is a LWP sleeping interruptably, call setrunnable() (by way
of the 'out:' target in psignal1) instead of calling unsleep() so
that it becomes LSSTOP in issignal() and continuable by
proc_unstop(). Addresses PR kern/19990 by Martin Husemann, with
suggestions from enami tsugutomo.
